PREMISES AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Premises and equipment [Abstract]
Premises and equipment, gross	$ 89,215	$ 88,151
Less accumulated depreciation and amortization	62,558	59,228
Net book value	26,657	28,923
Depreciation expense	3,703	4,205	$ 4,044
Rent expense	1,200	1,200	$ 1,300
Rent commitments, before considering renewal options [Abstract]
2018	1,121
2019	902
2020	737
2021	732
2022	732
2023 and thereafter	4,369
Total	8,593
Leases in premises and equipment [Abstract]
Buildings	5,572	5,572
Accumulated depreciation	(874)	(540)
Total	4,698	5,032
Schedule by year of future minimum lease payments under the capitalized lease [Abstract]
2018	367
2019	367
2020	376
2021	388
2022	391
2023 and thereafter	4,031
Total minimum lease payments	5,920
Less amount representing interest	1,403
Present value of net minimum lease payments	4,517
Land
Premises and equipment [Abstract]
Premises and equipment, gross	4,803	4,803
Buildings
Premises and equipment [Abstract]
Premises and equipment, gross	41,045	40,831
Projects in progress
Premises and equipment [Abstract]
Premises and equipment, gross	357	0
Equipment and furniture
Premises and equipment [Abstract]
Premises and equipment, gross	37,545	37,072
Leasehold improvements
Premises and equipment [Abstract]
Premises and equipment, gross	$ 5,465	$ 5,445